A circuit board card may comprise a single printed circuit board(PC) or multiple circuit boards connected in a module form sometimes having multiple output connectors. Insertion and removal of a circuit board card from a connecting socket is typically done by hand after these components have been manually connected. For a circuit board card housing one or several circuit boards, the edge of the card may contain a different connector for each board. The connector for each card comprises a plurality of conductive sockets or prongs. These sockets or prongs are mated to corresponding sockets or prongs in a receptacle which is usually mounted to a chassis-like housing. This receptacle which sometimes is called an edge connector, provides mechanical support for the circuit board card. The term "circuit board card" is used herein to refer to both individual circuit boards of the plug-in variety and modules of multiple circuit boards having one or more connectors mounted along an end portion.
In the past, to insert and remove a circuit board card, it has been necessary to firmly grip the circuit boards themselves. For insertion, sufficient force is applied to assure a reliable connection. Removal also required a firm grip and the application of pulling forces. However, the pulling forces often included a rotational force from having to free the card from the receptacle. Such removal might result in an undesirable twisting movement relative to the plane of the card. Such torsional forces can bend the circuit board cards and produce mechanical damage such as cracking on the corners or edges of a circuit board or card. This can lead to costly repair to the cards, the connector receptacle, and even the chassis-like housing in which these components are located.
Further, it is becoming more common for circuit board and card assemblies to be located in small physical spaces where insufficient room exists to generate the leverage necessary to properly decouple the card from the receptacle without causing damage to these components and to the system in which they are located.
Until now, the torsional problems and resulting wear or damage to components have been tolerated as necessary inescapable penalties associated with standard connector designs.
There is now provided a decoupling mechanism for reducing damage caused to cards comprising single or multiple circuit boards--and the respective connector-receptacles to which they are mated.
According to the invention, a prong and socket electrical connection is disengaged by positioning a rotatable arm about an interface of the prong and the socket, and the arm is rotated against the prong or the socket to force one away from the other.
There is also provided a mechanism for effecting this method wherein a tool for mechanically decoupling an electrical prong connection from an electrical socket connection comprises a rotatable arm for positioning about an interface of the prong connector and the socket connector, and a base for supporting the arm, wherein rotation of the arm pushes against both the base and one of the connectors causing a separation of the connectors from one another.
According to a preferred embodiment the rotatable arm of the decoupling mechanism comprises a rotatable rod with a cam shaped arm fixed at each end and a lever handle connected to one of the rod ends. The base comprises a plate that has an aperture for receiving mated prongs and sockets. The plate further comprises raised supports providing a restrictive path for the rod to travel along. According to a preferred method this mechanism is inserted about the interface of the card connector and the receptacle connector. To remove the card, the lever is pushed or pulled causing the rod to rotate within the raised supports. With this rotation the cam arms attached to the rod turn from a retracted position to push against the plate and the receptacle until the arms reach an extended position. The force exerted against the plate and the receptacle causes a separation of the card apart from the receptacle.
A guide can also be incorporated with the mechanism to facilitate decoupling of the card in a continuous linear direction apart from the receptacle with the card remaining parallel to the receptacle during disengagement. Four guide pins can be attached to the receptacle extending in the direction of the card, and four through-holes for the pins would be located in the plate. Movement of the pins through the holes guides decoupling of the card from the receptacle.
Embodiments for decoupling both a card comprising multiple circuit boards and for decoupling typical wall-plug connectors are also disclosed.
Of course cams have found a wide variety of applications in mechanical systems. Cams have even been used in conjunction with electrical connectors. See, for example, U.S. Pat. Nos. 3,997,747 and 4,261,631. As best understood, prior efforts to facilitate movement of electrical connectors with cam mechanisms has required both complex mechanical assemblies and modifications to otherwise standard connectors. Such specialized arrangements are often impractical in a cost-sensitive, high-volume manufacturing environment. Moreover, these known applications of cam mechanisms have not provided a solution to remove the torsional forces present during hand removal of a card. Further, the known systems are not useful in high density systems which place cards in small compact spaces.